Buttonhole-sewing machine



E- B. ALLEN.

BUTTONHOLE SEWING MACHINE. APPLICATION FILED NOV. 16. 1914. 1,394,135, Patented Oct. 18, 1921.

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4o WITNESSES: INVE/V 70/? E. B. ALLEN. BUTTONHOLE SEWING MACHINE.

APPLICATION FILED NOV. 16. I914- Patented Oct. 18, 1921.

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INVENTOI? W/ TIL/E8858:

A TTOR/VEV UNITED STATES" PATENT OFFICE.

EDWARD B. ALLEN, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURIEG COMPANY,'A CORPORATION OF NEW JERSEY.

BUTTONHOLE-SEWING MACHINE.

Specification of Letters Patent.

Patented Oct. 18, 1921.

Application filed November 16, 1914. Serial No. 872,333.

To all col- 10m it may concern. 1 7

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Buttonhole-Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

In automatically operating buttonhole cutting and stitching machines designed for operation at high speed, it is desirable that the operation of the various parts be performed in as close succession as possible and with such gradual movements as to avoid harsh or abrupt engagement of the parts. This is particularly true in relation to buttonhole cutting elements which are required to engage the work under a comparatively high pressure, and which should thus have comparatively short opening and closing movements in order that such movements may be derived from cams or other actuating elements which are not too harsh or abrupt in their action to prevent the smooth operation and effective action of the cutting elements. In order that the cutting elements may be prevented from interference with the stitch-forming mechanism and may'avoid obstruction of the operators view in the handling of the work under the condition above described, the cutting device has been heretofore given a traveling movement into and out of cutting position, as fully disclosed in my Patent No. 1,048,? 86, of December 31, 1912.

To adapt a machine of this character for operation upon thick as well as thin material, the upper work-clamping members should be adapted to rise for reception of the work above the normal open position of the upper cutting element, under which condition the clamp should be at least partially closed in the travel of the cutting elements into cutting position so as to avoid interference with the upper clamp member. In my Patent N0. 1,24[0,64;2, issued Sept. 18, 1917, the upper clamp members are given a preliminary partial closing movement by a connection with the cutter-carrying levers in their travel into cutting position, and a final closing action as the cutters close upon the work.

One of the principal objects of the present improvement is to effect the closing of the clamp by means which will be so gradual in their action as to avoid the harsh engagement of cam members and their followers, while being performed sufficiently in advance of the operative movement of the buttonhole cutting elements to insure the timely displacement of the upper clamp members to escape collision with the upper cutting element. The invention has for a further object to provide simple and effective means for promptly opening the work-clamp at the completion of a stitching operation.

The present improvement, in its preferred form, is embodied in a machine constructed in substantial accordance with that disclosed in my said Patent No. 1,240,642, wherein the buttonhole cutting elements are carried by reciprocally moving levers mounted upon a traveling fulcrum-block and deriving their traveling and opening and closing movements from cams upon a cutter-shaft suitably controlled in its connection with the driving means for performing a single rotation only preparatory to each buttonhole stitching operation. The cutter-shaft has fixed thereon a clamp-closing cam independent of the cutter-operating cams and acting upon a rock-lever having a fixed fulcrum and itself adapted to engage a tappet-arm upon the clamp-operating rock-shaft for turning the same to close the clamp.

The clamp operating rock-shaft preferably has a second tappet-arm disposed in angular relation with that first mentioned and adapted for engagement with a reciprocatory tripping element adjustably mounted upon a slide-bar having a link connection with a swinging arm fixed upon the upper end of a short rock-shaft having upon its other end a second arm adapted for engagement with a cam projection upon the feed-wheel from which the work-clamp derives its longitudinal feeding and side-shift movements.

The clamp-closing cam upon the cuttershaft is so positioned relatively to the cutteractuating cams that, through its connection with the clamp-operating rock-shaft, the upper clamp members begin their closing movement preferably just before the beginning of the advance of the cutting elements, so that the cutting elements have an unobstructed travel to cutting position and perform their cutting movements while the work is securely clamped in position. The stitching of the cut edges of the buttonhole slit having succeeded the cutting action,

preparatory to the arrest of the feed-wheel, its cam element operates through the detappet upon the clamp-operating rock-shaft,

whereby the latter is turned to cause theupper clamp members to rise under the action of their lifting springs.

The invention will be understood by reference to the accompanying drawings, in which Figure 1 is a side elevation of the lower portion of a buttonhole sewing machine embodying the present improvement, and Fig. 2 a plan'of the same. Fig. 3 is a perspective view of'the clamp-opening and closingdevices with their actuating means,

and Fig. 4 is a similar view of a portion of thecutter-shaft with the cutter closing and clamp-closing cams thereon. bottom plan of the feed-wheel with its actuating means.

As represented in the drawings the frame ofthe machine includes the hollow rectan gular base 1 having a suitably apertured top forming the bed-plate 2. The base is shown provided with the removable forward section 3 for access to the looper mechanism cooperating with a reciprocating and laterally' jogging thread-carrying needle 4 sustained above the bed-plate. The stitch forming mechanism, as thus constituted, is or may be constructed and operated as represented in my United States Patent No. 1,030,046, of June 18, 1912, but its specific character is not material to the present improvement. I

Suitably journaled in the base is the longitudinally extending main-shaft 5 formed with quartering cranks 6 embraced by the lower ends of pitman-rods 7 by means of i which it is connected with the upper needleactuating shaft. The main-shaft 5 carries the cam-cylinder 8 having the peripheral cam-groove 9 entered by a roller-stud upon an arm of the rocker 10 fulcrumed beneath the bed-plate.

The rocker 10 is connected by means of the pitman 11 with the clutch-lever 12 which actuates the clutch-dogs l3 embracing a depending flange of the feed-wheel 14. The

feed-wheel'is shown provided in its upper face with the usual feeding cam-groove15 and side-shift cam-groove 16. groove 15 is entered by the roller-stud 17 depending from the swinging arm 18 fulcrumed at 19 and provided with the longitudinally adjustable stud 20 entering a transverse slot 21 in the work-clamp slideplate 22. The cam-groove 16 is entered by a stud depending from the rock-lever 23 having a sliding and pivotal connection with the usual cross slide-plate mounted for endwise'rmovement upon the slide-plate 22 in a manner well known.

The cam-' The slide-plate 22 sustains the edgewise and reciprocally movable clamp-plates 24 and 25 affording thelower clamping members of the work-holder. Each of. these clamp-plates has adjustably secured thereon a bearing bracket 26 sustaining near its foot the fulcrum-pin 27 of one of the upper forwardly extending clamp-arms 28 carrying the pivoted foot-29'constituting one of the upper clamping members. J ournaled in the bearing bracket 26 above the adjacent portion of the clamp-arm 28 is the transverse clamp-operating rock-shaft 30 provided upon one side with the cam projection 31 adapted for engagement with the clamparm for pressing the same downward to close the clamp in opposition to the lifting spring 32.

The rock-shafts 30 are in-the present construction made separate to enable the separable sections ofthe clamp to be shifted relatively, and they are coupled together when in operative position by means of a crank-arm 33 fixed upon the one and provided With a lateral pin 34 entering a fork 35 in a similar crank-arm 36 fixed upon the other of said rock-shafts. The rockshaft 30 at the right, as seen from the front 7 end of the machine, is'provided with a laterally extending bent tappet-arm 37 and with an upwardly extending tappet-arm 38 by means of which the shaft may be rocked in opposite directions for closing and opening the clamp. The said rock-shaft is also provided with'the finger-lever 39 by means of which the clamp maybe manually operated, the movements of one rock-shaft being communicated to the other by the connection before described.

Suitably journaled in the frame slightly above the bed-plate 2 is the transverse cutter-shaft 40 provided upon one end with the loose groovedbelt-wheel 41 deriving continous rotary motion from a belt leading from the source of power independently'of the main-shaft 5. Between the hub 42 of the belt-wheel 41 and the disk 43 fixed upon the shaft 40 is a clutch device controlled by means of the flange 44' of the controlling lever '45 fulcrumed at '46 and pressed'normally into, clutch-disengaging position by means of the spring 47 interposed between the flange 44 and the boss 48rising from the bed-plate 2. This clutch device operates to control the connection of the cutter-shaft with its driving means in such manner that the shaft performs asingle rotation only preparatory to each buttonhole stitching operation. V

The cutter mechanism represented inthe drawin s is substantially that of my said Patent 1V0, 1,048,786; It comprisesa trav the upper and lower cutter-carrying levers 51 and 52. The upper lever 51 carries the cutting knife 53 and the lower lever carries the coperating block 54. The fulcrum-carrying slide-block is fitted within a suitable slideway of the bed-plate.

The rearward ends of the cutter-levers are drawn together by means of a spring 55 which maintains the flat adjacent edges of the cutter-levers permanently in contact or operative relation with their respective actuating cams 56 and 57 fixed upon the cuttershaft 40. The cutter-shaft has also secured thereon the cam-disk 58 formed in one face with the cam-groove 59 entered-by the lateral stud 60 of the link 61 having at its rearward end a yoke 62 embracing the cuttershaft and its forward end apertured to receive the stud-bolt 63 projecting laterally from the rearward extension of one of the fulcrum-sustaining flanges 49, whereby the fulcrum-block and the cutter-levers are given traveling movements toward and from stitching position preparatory and subsequent to each buttonhole cutting operation.

The cutter-shaft has secured thereon also a collar 64 having the clamp-closing cam projection 65. Secured upon the bed-plate 2 is a bearing bracket 66 carrying the fulcrum stud-screw 67 upon which is mounted the clamp-closing rock-lever comprising a rearwardly extending arm 68 disposed in operative relation with the collar 64 and the cam projection 65, a forward arm 69 of such rock-lever having its rounded eX- tremity disposed slightly above the upper face of the tappet-arm 37 when the clamp is in initial position.

The spring 70 coiled around the fulcrumstud 67 and connected at its opposite ends respectively with the bracket 66 and rocklever arm 69, serves to maintain the rocklever in permanent contact relation with the collar 64 and its cam projection 65, the rotation of the latter causing the rocking of the lever 68 69 and its consequent engagement with the tappet-arm 37 for turning the clamp-operating rock-shafts 30 to close the Workclamp. The clamp is maintained closed in opposition to the springs 32 by reason of the cam projections 31. moving slightly beyond their dead-center positions, as is common in this class of work-holders.

Fitted within a suitable guideway in the top of the bed-plate is a slide-bar 71 having secured thereon by screws 72 the foot 73 of a post 74 formed at the upper end with the transverse boss 75. Adjustably mounted in the boss 75 is the tripping pin 76 having applied to its threaded rearward portion the nuts 77 and 78 engaging the opposite ends of the boss 75 for maintaining the pin in the desired position of endwise adjustment. The tripping pin is directed toward and has a range of movement embracing the range of movement of the clamp-opening tappete arm 38, and it is maintained normally retracted from engagement with the tappetarm by means of a spring 7 9 having one end connected with the post 74 and the opposite end with the fixed bearing bracket 66.

The slide-bar 71 carries adjacent the post 74 the stud-screw 80 which is embraced by an apertured end of the link 81 carrying at its opposite end the stud-screw 82 which is embraced by the apertured boss 83 at the extremity of the crank-arm 84 having its hub secured by means of the set-screw 85 to the vertical rocking pin or shaft 86 journaled in the bed-plate 2. The rock-shaft 86 has fixed upon its lower end the hub of an arm 87 normally resting upon the periphery of the feed-wheel 14 and adapted to be engaged by.

the peripheral cam projection 88 carried by the feed-wheel. By the action of the spring 79, the arm 87 is maintained yicldingly in contact with the periphery of the cam-wheel during the button-hole stitching period, at the end of which its engagement with the cam projection 88 causes the rocking of the shaft 86 and the consequent advance of the tripping element 76 into engagement with the tappet-arm 38 by means of which the clamp rock-shafts 30 are turned to disengage their cam projections 31 from the respective clamp-arms which are thereupon lifted by the action of the springs 32.

The machine is started by shifting the controlling lever 45 whereby the cutter-shaft clutch is operated to permit the coupling of the cutter-shaft with the continuously rotating belt-wheel 41, the driving connection being interrupted at the completion of a single rotation of the cutter-shaft. In the initial portion of the rotation of the cutter-shaft the cam projection 65 engages the arm 68 of the clamp-closing rock-lever and tilts the lat ter into engagement with the tappet-arm 37, the advance of the cutting elements toward cutting position beginning about at this time, the upper clamp-members being depressed in time to insure against interference by the advancing upper cutting member. The cutting elements having advanced into register with the needle-aperture of the work-clamp, the cutter-levers 51 and 52 are acted upon by their respective actuating cams 56 and 57 whereby the cutting members are closed upon the work, being subsequently retracted by the action of the spring 55 upon the levers 51 and 52 which there after recede into initial retracted position under the action of the cam-wheel 58. In

practice the cam-wheel 58 is provided with stitching operation, the cam-projection 88 engages the arm 87 of the rocking pin or shaft 86 which acts through its connections to advance the tripping pin 7 6 into engagement with the tappet-arm 38 of the clampoperating roclcshaft 30 whereby the clamp is automatically opened.

in buttonhole sewing machines of the present type, as represented in my said Patents No. 1,030,046, and No. 1,2 l0,6&2, means are provided for producing relative shifting movements between the wor r-holder and the working position of the reciprocating and laterally joggingneedle, such means comprising different sets of mechanism connccted with and controlled by the feedwheel, the one producing step-by-step longitudinal and lateral movements in the stitching of the straight portion of the buttonhole and the divergently inclined portions of the eye, and the other producing turning movements of the stitch-forming elements while the work-holder remains at rest in the stitchin of the semi-circular portion of the eye. The means for turning the stitch-forming mechanism in the stitching of the eyed end of a buttonhole comprises a frame including the upper and lower laterally extending members 89 and 90 connectcd by the intermediate uprightmember 91, the lowermember being shown provided with a roller-stud 92 entering a groove 93 in the lower face of the feed-wheel 14 by means of which the frame is adapted to be moved to and fro. The upper and lower frame-members are in practice similarly provided with rack-and-pinion connections with the upper and lower stitcl1forming devices for turnin them in unison. As represented in 'Fig. 1, the frame-member 89 has rigidly secured to its forward end the rack 94c meshing with the pinion 95'fast upon the sleeve or bushing 96 in which the needle-bar is jo-urnaled and with which it is adapted to turn.

It will be observed that, in the embodiment of the present improvement as herein described, the tripping means for effecting the opening of the workholder is actuated by a connection with the feed-wheel which is independent of the relative shifting means between-the stitch-forming mechanism and the work-holder whereby the stitches are spaced apart.

As before stated, one of the important features of the present improvement is the actuation of the cutting elements and the work-clamp in such manner that the cams employed have comparatively short throws, thereby preventing harsh engagements of the parts, while the employment of a separate cam for effecting the closing of the clamp permits this operation to be performed so gradually as to avoid shock. Another advantage of employment of several cams for imparting the traveling and close ing movements to the cutting device and for effecting the closing of the clamp is that the initial impulses for these several actions may be distributed throughout a portion of the rotation of the cutter-shaft without imposing an excessive load thereon at any one part of its rotationa In the machine herein shown and described, the cuttereactuating shaft'is normally idle, being set'in motion only for performance Of'a single rotation immediately before the operation of the stitch-forming mechanism, but it is of course immaterial to the present invention as regards certain of its characteristic features, whether this shaft rotates continuously or interruptedly, so long as its independent action upon the cutting device and the'clamp-closing means occur preparatory to the stitching operation.

As herein shown and described, the trip ping pin for opening the work-clamp is.

shown mounted inclependentlyof the clamp and positioned for acting. direct-1y upon one of the tappet-arms of the clamp-operating rock-shaftbut it is evidently imma-.

terial, in the broader aspect of the present invention, how such tripping; pin is sustained, so long as it is capable of movement relatively to the work-clamp, and whether it act directly upon such tappet-arm or indirectly through some intermediate connecting element, its function being to transmit to therock-shaft its own movement derived from an element of the feeding mechanism.

It is thus evident that the present im: provement is not limited to the specific embodiment herein shown and described, but is susceptible of considerable modification in the construction and arrangement .of its component parts without departure from the scope of the invention.

Having thus set forth the nature of the invention, what I claim herein is 1. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp, a buttonhole cutting device comprising cutter-carrying levers, a shaft, actuating elements thereon in permanent operative relation with said levers, a clamp-closing element upon said shaft, and a connection. between the latter and the work-clamp. V

2. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp, a feed-wheel, actuating means therefor, a cutter-shaft, actuating means therefor, buttonhole cutting elements operatively connected with and actuated by the cutter-shaft, and a connection between the cutter-shaft and the work-clamp independent of the connections between said shaft and the cutting elements whereby the workclamp is closed preparatory to a buttonhole cutting action.

3. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp, a buttonhole cutting device comprising cutter-carrying levers, a traveling fulcrum-block for said levers, a shaft, means connected with said shaft for imparting traveling movements to the fulcrum-block, means connected with said shaft for operatin said cutter-carrying levers to perform a cutting action, and means connected with said shaft independently of its connections with said fulcrum-block and cutter-carrying levers whereby the workclamp is closed preparatory to a cutting action.

4. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp, a buttonhole cutting device comprising cutter-carrying levers, a traveling fulcrum-block for said levers, a shaft, means connected with said shaft for imparting traveling movements to the fulcrum-block, means connected with said shaft for operating said cutter-carrying levers to perform a cutting action, a rock-lever adapted for operative connection with said workclamp for closing the same, a fixed fulcrum for said rock-lever, and a cam element upon said shaft and adapted to impart operative movements to said rock-lever.

5. In a buttonhole sewing machine, the combination with stitch-forming mechanism, including a needle, of a work-clamp comprising upper and lower members and a clamp-operating rock shaft, a feed-wheel, shifting means connected with the feedwheel for producing in periods including successive stitch-forming cycles relative feeding movements between the working position of the needle and the work-clamp; a tappetarm on the clamp-operating rock shaft, a tripping element movably supported independently of the work-clamp and adapted for engagement with said tappet-arm for opening the clamp, and means connected with and actuated by said feed-wheel independently of said shifting means for shifting said tripping element into operative relation with the tappet-arm for opening the work-clamp.

6. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp comprising upper and lower members and a clamp-operating rockshaft, a feed-wheel, connections between the feed-wheel and the work-clamp for producing relative feeding movements between the latter and the stitch-forming mechanism, a

tappet-arm on the clamp-operating rockshaft, a tripping element adapted for engagement with said tappet-arm for opening the clamp, a slide-bar sustaining said trip ping element, a rocking pin having an arm connected with said slide-bar, and a second arm upon said rocking pin disposed in operative relation with the feed-wheel.

7. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp a feed-wheel, a ni'ain-shaft to which the same is operatively connected, means connected with the feed-wheel for producing between the stitch-forming mechanism and the work-clamp relative feeding movements, a buttonhole cutting device comprising cutter-carrying levers, a cutter shaft driven independently of the main-shaft, actuating elements thereon adapted for action upon said levers, a clamp-closing element upon said cutter shaft, and a connection between the latter and the work-clamp.

8. In a buttonhole sewing machine, the combination with stitch-forming mechanism, of a work-clamp, feeding mechanism connected therewith, a cutter-shaft, actuating means therefor driven independently of the feeding mechanism, buttonhole cutting elements operatively connected with and actuated by the cutter-shaft, and a connection between the cutter-shaft and the work-clamp independent of the connections between said shaft and the cutting elements, whereby the work-clamp is closed preparatory to a buttonhole cutting action.

9. In a buttonhole sewing machine, the combination with stitch-forming mechanism, including a needle, of a work-clamp comprising upper and lower work-gripping members and a clamp-operating rock-shaft, a feed-wheel, shifting means connected with the feed-wheel for producing in periods including successive stitch-forming cycles relative feeding movements between the working position of the needle and the work-clamp; a tappet-arm on the clamp-operating rockshaft, a tripping element movable relatively to the work-clamp and adapted for operative connection with said tappet-arm for opening the clamp, and means connected with and actuated by said feed-wheel independently of said shifting means for imparting to said tripping element its operative movements.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

EDWARD B. ALLEN.

Vitnesses STANLEY N. SMITH, WILLIAM A. ANDRES. 

